Direct reading triangulation focusing mechanism

ABSTRACT

An improvement in a distance determining mechanism for a camera having a focusable objective lens, the mechanism including a pendulous member having a cam surface formed with fine pitched teeth with which similar teeth on a cam follower cooperate to cause adjustment of the lens to a focus condition and, after adjustment, to cause substantially positive locking of the lens in adjusted position while enabling manual focusing through actuation of an externally extending focusing control. By the improvement, the mechanism permits more positive movement of an indicator relative to a focusing scale responsive to the focus condition of the objective lens which is positioned responsive to orientation of the pendulous member of the focusing mechanism.



1. Improvements in a range determining device using the principle of triangulation adapted for use in an optical instrument having a focusable objective lens and a housing adapted for orientation about a predetermined axis to orient the optical axis to an angle defining the hypotenuse of a triangle, the device including a pendulous member being supported in said housing to be oriented for focusing of said objective lens, and having a cam surface corresponding to the angle of inclination of said optical axis, the improvement comprising: a distance reference scale means; an indicator means adjustable responsive to the focus condition of the focusable objective lens and adjustable independently of adjustment of the pendulous member.
 2. A combination as in claim 1 comprising means coupling said indicator means and said objective lens for orientation of said indicator means responsive to the focus condition of said objective lens.
 3. A combination as in claim 2 wherein said coupling means includes means engaging said indicator means and means biasing said indicator means relative to said engaging means.
 4. A combination as in claim 3 wherein said biasing means is a tension spring urging said indicator means against said engaging means.
 5. Improvements in a range determining device using the principle of triangulation adapted for use in an optical instrument having a focusable objective lens and a housing adapted for orientation about a predetermined axis to orient the optical axis to an angle defining the hypotenuse of a triangle, the device including a pendulous member being supported in said housing to be oriented for focusing of said objective lens, and having a cam surface corresponding to the angle of inclination of said optical axis, the improvement comprising: a distance reference scale means; an indicator means arranged for movement relative to said scale means; means displaceable positively by said objective lens cooperating with said indicator means for displacing said indicator means upon adjustment of said objective lens through a focusing range normally corresponding to the orientation of said pendulous member.
 6. Improvements in a range determining device using the principle of triangulation adapted for use in an optical instrument having a focusable objective lens and a housing adapted for orientation about a predetermined axis to orient the optical axis to an angle defining hypotenuse of a triangle, the device comprising: a pendulous member being supported in said housing to be oriented responsive to the angle of inclination of said optical axis; means cooperating with said pendulous member for displacing said objective lens into focus orientation responsive to the oriented position of said pendulous member; a distance reference scale means; an indicator means independent of said pendulous member and said objective lens being movable relative to said reference scale means; and means coupling said indicator means to said objective lens for adjustment of said indicator means reponsive to the position of said objective lens when said lens is adjusted in responsive to orientation of said pendulous member.
 7. A combination as in claim 6 wherein said coupling means includes means engaging said indicator means, means biasing said indicator means relative to said engaging means, and means coupled to a focusing lens component for adjusting said engaging means responsive to the positive of said focusing lens component. 